<?php
namespace Home\Controller;
use Think\Controller;


class CommonController extends Controller {
    public function _initialize()
    {
        $jssdk = new JSSDK(C('appID'), C ( 'appSecret' ));
        $signPackage = $jssdk->getSignPackage();
        $this->assign('signPackage',$signPackage);
    }
}

//微信方法

class JSSDK {
    private $appId;
    private $appSecret;
    public function __construct($appId, $appSecret) {
      $this->appId = $appId;
      $this->appSecret = $appSecret;
    }
    public function getSignPackage() {
      $jsapiTicket = $this->getJsApiTicket();
      $url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
      $timestamp = time();
      $nonceStr = $this->createNonceStr();
      // 这里参数的顺序要按照 key 值 ASCII 码升序排序
       $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";
      $signature = sha1($string);
      $signPackage = array(
        "appId"     => $this->appId,
        "nonceStr"  => $nonceStr,
        "timestamp" => $timestamp,
        "url"       => $url,
        "signature" => $signature,
        "rawString" => $string
      );
      return $signPackage; 
    }
    private function createNonceStr($length = 16) {
      $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
      $str = "";
      for ($i = 0; $i < $length; $i++) {
        $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
      }
      return $str;
    }
    private function getJsApiTicket() {
      // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
      $data = json_decode(file_get_contents("jsapi_ticket.json"));
      file_put_contents("./data.txt", $data, FILE_APPEND);
      if(!$data){
      	die('获取jsapi_ticket.json失败');
      }
      if ($data->expire_time < time()) {
        $accessToken = $this->getAccessToken();
        $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
        $res = json_decode($this->httpGet($url));
        $ticket = $res->ticket;
        if ($ticket) {
          $data->expire_time = time() + 7000;
          $data->jsapi_ticket = $ticket;
          $fp = fopen("jsapi_ticket.json", "w");
          fwrite($fp, json_encode($data));
          fclose($fp);
        }
      } else {
        $ticket = $data->jsapi_ticket;
      }
      return $ticket;
    }
    private function getAccessToken() {
      // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
      $data = json_decode(file_get_contents("access_token.json"));
      if ($data->expire_time < time()) {
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
        $res = json_decode($this->httpGet($url));
        $access_token = $res->access_token;
        if ($access_token) {
          $data->expire_time = time() + 7000;
          $data->access_token = $access_token;
          $fp = fopen("access_token.json", "w");
          fwrite($fp, json_encode($data));
          fclose($fp);
        }
      } else {
        $access_token = $data->access_token;
      }
      return $access_token;
    }
    private function httpGet($url) {
      $curl = curl_init();
      curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
      curl_setopt($curl, CURLOPT_TIMEOUT, 500);
      curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
      curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
      curl_setopt($curl, CURLOPT_URL, $url);
      $res = curl_exec($curl);
      curl_close($curl);
      return $res;
    }
}